Question

 <label class="user-reg-label fl">Percentage:<span class="required">*</span></label>
     <input class="user-reg-input fl" type="text" name="Percentage[]" id="Percentage1" value="" maxlength="5" />

this is my html code.
i need to validate this input field with javascript to enter only 5 values like 99.99

Answer 1

This is formatting, not validating, but it seems to be what the OP is really looking for ( I think ).

var input = document.getElementById("Percentage1"),
    onlyNumbers = input.value.replace(/\D/g,""), // Remove all nondigits
    cleanNumbers = onlyNumbers.substr( 0, 4 ); // Limit to four digits

// Add decimal if more than two digits in length
if( cleanNumbers.length > 2 )
{
    cleanNumbers = cleanNumbers.substr( 0, 2 ) + "." + cleanNumbers.substr( 2 );
}

input.value = cleanNumbers;